/**
 * JavaScript Document
 * @author sijian zhang
 */

 $sj.Tweene = {
		/*
		* @Linear：无缓动效果；
		* @Quadratic：二次方的缓动（t^2）；
		* @Cubic：三次方的缓动（t^3）；
		* @Quartic：四次方的缓动（t^4）；
		* @Quintic：五次方的缓动（t^5）；
		* @Sinusoidal：正弦曲线的缓动（sin(t)）；
		* @Exponential：指数曲线的缓动（2^t）；
		* @Circular：圆形曲线的缓动（sqrt(1-t^2)）；
		* @Elastic：指数衰减的正弦曲线缓动；
		* @Back：超过范围的三次方缓动（(s+1)*t^3 - s*t^2）；
		* @Bounce：指数衰减的反弹缓动。
		
		* @每个效果都分三个缓动方式（方法），分别是：
		* @easeIn：从0开始加速的缓动；(In)
		* @easeOut：减速到0的缓动；(Out)
		* @easeInOut：前半段从0开始加速，后半段减速到0的缓动。(InOut)
		* 
		* @t: current time（当前时间）；
		* @b: beginning value（初始值）；
		* @c: change in value（变化量）；
		* @d: duration（持续时间）。
		*/
		action : function(obj , styleType , funs , changeInValue , duration  , beginningValue , currentTime , AcType , ease , step){
			var thisObj = document.getElementById(obj) || obj;
			var c = Number(changeInValue) || 100 ;
			var d = Number(duration) || 100 ;
			var b = Number(beginningValue)  || Number(thisObj.style[styleType].replace(new RegExp("px"),"")) || 0;
			var t = currentTime || 0;
			var AcType = AcType || "Quad" ;
			var ease = ease || "In" ;
			var step = step || 1;
			
			if(styleType == "left" || styleType == "top" || styleType == "right" ||styleType == "bottom"){
				thisObj.parentNode.style.position = "relative"
			}
			var change = setInterval(function(){
				if(t<d){
				   t++;
				   thisObj.style[styleType] = Math.ceil($sj.Tweene[AcType][ease](t,b,c,d)) + "px";
				  }else{
					if(funs != ""){
						eval(funs + "()")
					}
				   clearInterval(change)
				  }
			} , step);
		},
		Linear: {In : function(t,b,c,d){ return c*t/d + b; }},
		Quad: {
			In: function(t,b,c,d){
				return c*(t/=d)*t + b ;
			},
			Out: function(t,b,c,d){
				return -c *(t/=d)*(t-2) + b;
			},
			InOut: function(t,b,c,d){
				if ((t/=d/2) < 1) return c/2*t*t + b;
				return -c/2 * ((--t)*(t-2) - 1) + b;
			}
		},
		Cubic: {
			In: function(t,b,c,d){
				return c*(t/=d)*t*t + b;
			},
			Out: function(t,b,c,d){
				return c*((t=t/d-1)*t*t + 1) + b;
			},
			InOut: function(t,b,c,d){
				if ((t/=d/2) < 1) return c/2*t*t*t + b;
				return c/2*((t-=2)*t*t + 2) + b;
			}
		},
		Quart: {
			In: function(t,b,c,d){
				return c*(t/=d)*t*t*t + b;
			},
			Out: function(t,b,c,d){
				return -c * ((t=t/d-1)*t*t*t - 1) + b;
			},
			InOut: function(t,b,c,d){
				if ((t/=d/2) < 1) return c/2*t*t*t*t + b;
				return -c/2 * ((t-=2)*t*t*t - 2) + b;
			}
		},
		Quint: {
			In: function(t,b,c,d){
				return c*(t/=d)*t*t*t*t + b;
			},
			Out: function(t,b,c,d){
				return c*((t=t/d-1)*t*t*t*t + 1) + b;
			},
			InOut: function(t,b,c,d){
				if ((t/=d/2) < 1) return c/2*t*t*t*t*t + b;
				return c/2*((t-=2)*t*t*t*t + 2) + b;
			}
		},
		Sine: {
			In: function(t,b,c,d){
				return -c * Math.cos(t/d * (Math.PI/2)) + c + b;
			},
			Out: function(t,b,c,d){
				return c * Math.sin(t/d * (Math.PI/2)) + b;
			},
			InOut: function(t,b,c,d){
				return -c/2 * (Math.cos(Math.PI*t/d) - 1) + b;
			}
		},
		Expo: {
			In: function(t,b,c,d){
				return (t==0) ? b : c * Math.pow(2, 10 * (t/d - 1)) + b;
			},
			Out: function(t,b,c,d){
				return (t==d) ? b+c : c * (-Math.pow(2, -10 * t/d) + 1) + b;
			},
			InOut: function(t,b,c,d){
				if (t==0) return b;
				if (t==d) return b+c;
				if ((t/=d/2) < 1) return c/2 * Math.pow(2, 10 * (t - 1)) + b;
				return c/2 * (-Math.pow(2, -10 * --t) + 2) + b;
			}
		},
		Circ: {
			In: function(t,b,c,d){
				return -c * (Math.sqrt(1 - (t/=d)*t) - 1) + b;
			},
			Out: function(t,b,c,d){
				return c * Math.sqrt(1 - (t=t/d-1)*t) + b;
			},
			InOut: function(t,b,c,d){
				if ((t/=d/2) < 1) return -c/2 * (Math.sqrt(1 - t*t) - 1) + b;
				return c/2 * (Math.sqrt(1 - (t-=2)*t) + 1) + b;
			}
		},
		Elastic: {
			In: function(t,b,c,d,a,p){
				if (t==0) return b;  if ((t/=d)==1) return b+c;  if (!p) p=d*0.3;
				if (!a || a < Math.abs(c)) { a=c; var s=p/4; }
				else var s = p/(2*Math.PI) * Math.asin (c/a);
				return -(a*Math.pow(2,10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )) + b;
			},
			Out: function(t,b,c,d,a,p){
				if (t==0) return b;  if ((t/=d)==1) return b+c;  if (!p) p=d*0.3;
				if (!a || a < Math.abs(c)) { a=c; var s=p/4; }
				else var s = p/(2*Math.PI) * Math.asin (c/a);
				return (a*Math.pow(2,-10*t) * Math.sin( (t*d-s)*(2*Math.PI)/p ) + c + b);
			},
			InOut: function(t,b,c,d,a,p){
				if (t==0) return b;  if ((t/=d/2)==2) return b+c;  if (!p) p=d*(0.3*1.5);
				if (!a || a < Math.abs(c)) { a=c; var s=p/4; }
				else var s = p/(2*Math.PI) * Math.asin (c/a);
				if (t < 1) return -0.5*(a*Math.pow(2,10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )) + b;
				return a*Math.pow(2,-10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )*0.5 + c + b;
			}
		},
		Back: {
			In: function(t,b,c,d,s){
				if (s == undefined) s = 1.70158;
				return c*(t/=d)*t*((s+1)*t - s) + b;
			},
			Out: function(t,b,c,d,s){
				if (s == undefined) s = 1.70158;
				return c*((t=t/d-1)*t*((s+1)*t + s) + 1) + b;
			},
			InOut: function(t,b,c,d,s){
				if (s == undefined) s = 1.70158; 
				if ((t/=d/2) < 1) return c/2*(t*t*(((s*=(1.525))+1)*t - s)) + b;
				return c/2*((t-=2)*t*(((s*=(1.525))+1)*t + s) + 2) + b;
			}
		},
		Bounce: {
			In: function(t,b,c,d){
				return c - fn.Tweene.Bounce.Out(d-t, 0, c, d) + b;
			},
			Out: function(t,b,c,d){
				if ((t/=d) < (1/2.75)) {
					return c*(7.5625*t*t) + b;
				} else if (t < (2/2.75)) {
					return c*(7.5625*(t-=(1.5/2.75))*t + 0.75) + b;
				} else if (t < (2.5/2.75)) {
					return c*(7.5625*(t-=(2.25/2.75))*t + 0.9375) + b;
				} else {
					return c*(7.5625*(t-=(2.625/2.75))*t + 0.984375) + b;
				}
			},
			InOut: function(t,b,c,d){
				if (t < d/2) return fn.Tween.Bounce.In(t*2, 0, c, d) * 0.5 + b;
				else return fn.Tweene.Bounce.Out(t*2-d, 0, c, d) * 0.5 + c*0.5 + b;
			}
		}
	}